scipy.stats has more than 90 distributions.
Do we want to increase it by almost a factor of 10? :)
While looking for the cdf of a distribution, I found this :
http://www.mathworks.com/matlabcentral/fileexchange/35008-generation-of-random-variates
He collected 870 distributions (under BSD license). Includes generic
random number generation.
Even though there are some variations of distributions counted
separately, given my quick browsing this looks impressive and a good
source for code and references.
Coding style is not great but it's 10 years or so of collecting distributions.
Josef